cmake - Should I cache CMAKE_BUILD_TYPE?

Question

If you don't set the CMAKE_BUILD_TYPE, then, by default, it doesn't get cached. Should I cache it? e.g. should I have:

if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE "Release" )
  set(CMAKE_BUILD_TYPE "Release" CACHE STRING "Type of build (Debug, Release etc." FORCE)
endif()

or just:

if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE "Release" )
endif()

Or does it not really matter?

Answer 1

Caching of CMAKE_BUILD_TYPE is usefull for cmake-gui: user of your project would able to change a build type in a nice manner.

There is a good template for setting default CMAKE_BUILD_TYPE from developers:

# Set a default build type if none was specified
if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
  message(STATUS "Setting build type to 'Debug' as none was specified.")
  set(CMAKE_BUILD_TYPE Debug CACHE STRING "Choose the type of build." FORCE)
  # Set the possible values of build type for cmake-gui
  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
    "MinSizeRel" "RelWithDebInfo")
endif()